Studies show about 15% of Open Houses produce a buyer at an Open House for that house. Yes, would-be sellers go to open houses to see how agents work and to "interview" for an agent. Some visitors are agents previewing house. Some are neighbors who have a friend or relative who may buy it. But unknown, the number of buyers who buy the house from having heard from a friend about a house that was seen at an Open House and then followed up on by the buyer. So, more people who see it, more likely a better outcome for seller. The opposite is also true. Fewer people who see it, less than ideal result. Example, a FSBO with sign and phone number. Buyer will have to come from the chance that a buyer will drive buy and notice it. Realtors market houses and owners sell them. Marketing is sophisticated, creative, thorough, pervasive, personal, individual, and persistant. Fascinating, isn't it?